As an integration level of an integrated circuit (IC) chip is increasingly high, power density of the chip is higher. In addition, the power density is also unevenly distributed across the entire IC chip. In a region whose power density is relatively high, a large amount of heat is generated within a range with an extremely small area, and consequently, a heat point with an extremely high temperature is formed on a surface of the chip. Temperatures of these “heat points” are much higher than an average temperature of the entire IC chip. If heat in heat-point regions cannot be rapidly spread because effective heat management and an effective heat dissipation design are not performed on the IC chip, temperatures in the heat-point regions of the chip easily become excessively high, and consequently, the chip cannot normally work.
Currently, a heat dissipation design of an IC chip is mainly adding a heat sink on an IC chip package. FIG. 1 shows a die-up plastic ball grid array package body 10 on which a heat sink 12 is integrated. In the package body 10, an IC die 11 is mounted on a underlay 15 by using a die bonding material 13, and is connected to a leading wire 17. The package body 10 can be connected to a printed circuit board (not shown in FIG. 1) by using a solder ball 14. The heat sink 12 is disposed on the underlay 15, and is configured to dissipate heat of the die 11. A plastic packaging material 16 seals the package body 10. In FIG. 1, a material of the heat sink 12 is a conductive material. Therefore, the heat sink 12 and the die 11 need to be insulated from each other by using the insulating plastic packaging material 16. In FIG. 1, the heat sink 12 is mostly located on the plastic packaging material 16, that is, the heat sink 12 is mostly located at a package layer formed by the plastic packaging material 16.
A heat dissipation method used for the package body shown in FIG. 1 is to design a heat path in an IC chip package structure, so as to spread heat of heat points by using the heat sink. According to this heat dissipation method, cooling is indiscriminately performed on the entire chip to remove the heat from the entire package body, so as to maintain a temperature of the chip under an upper limit of working.
However, the added heat sink still cannot be infinitely close to the IC die due to some physical limitations of an IC chip package technology and the IC chip package structure, and the IC die is a heat source. Therefore, a method for adding a heat sink to an IC chip package is not enough for reducing the temperatures of the heat points on the surface of the IC chip, or has a limited effect in an aspect of reducing the temperatures of the heat points. As a result, working of the IC chip is still limited by the temperatures of the heat points on the surface of the IC chip.
In conclusion, in a current heat dissipation method of an IC chip, because a heat sink is mainly added to an IC chip package structure, and the heat sink cannot be infinitely close to an IC die, this heat dissipation method has a limited effect in an aspect of reducing a temperature of a heat point on a surface of the IC chip.